[FEATURE]: Reopen plugin enable/disable support; PR #12490 remains unmerged

Feature has not been delivered yet

This request follows up on #7687, #11743, and the still-open PR #12490.

• #11743 proposed disabled_plugins, plus plugin list, plugin disable, and plugin enable commands.
• In this comment, the author acknowledged that the request duplicated #7687, closed #11743, and stated that they would work on a PR.
• PR #12490 was subsequently opened to implement the feature and is still open and unmerged.
• Nevertheless, #7687 was closed by github-actions[bot] as completed on April 4, 2026.
• As of OpenCode 1.18.21, the feature is still absent: the official config schema has plugin and disabled_providers, but no disabled_plugins; the CLI also has no plugin list/enable/disable management commands.

Use case

Users need to keep a plugin declaration for a reversible configuration while temporarily preventing the plugin from loading.

A concrete example is migrating from LM Studio to oMLX. The LM Studio provider can be disabled with disabled_providers, but the opencode-lmstudio plugin must currently be removed from the plugin array to stop it from loading. This loses the declarative record from valid JSON. JSON comments are not available, and switching to JSONC solely for this workaround should not be necessary.

Desired configuration:

{
  "plugin": [
    "opencode-lmstudio",
    "@warp-dot-dev/opencode-warp"
  ],
  "disabled_plugins": [
    "opencode-lmstudio"
  ]
}

Requested action

Please reopen #7687 until the feature is actually delivered and review/merge PR #12490. If that PR is no longer suitable for the current codebase, please provide the required changes or invite a refreshed PR instead of leaving the tracking issue marked as completed.

Acceptance criteria

• Add disabled_plugins: string[] to the supported configuration schema.
• Skip loading external plugins whose configured package/module identifier is listed in disabled_plugins.
• Add CLI commands to list, disable, and enable configured plugins without uninstalling them.
• Preserve existing plugin entries when disabling a plugin.
• Document the feature and add configuration/plugin-loading tests.

Related: #7687, #11743, #12490